Many electrical applications require a galvanic isolation of electrical subsystems. By way of example, wireless charging applications require the transfer of energy from a mains power supply to an electronic device comprising a battery, without any wired coupling, between a charging unit (receiving power from the mains power supply) and the electronic device. The energy is typically transferred from the charging unit to the electronic device through inductive coupling. The charging unit may use an induction coil (the primary side of a transformer) to create an alternating electromagnetic field. A second induction coil (the secondary side of the transformer) in the electronic device takes energy from the electromagnetic field and converts the energy into an electrical current to supply power to charge the battery of the electronic device. The first and the second induction coils form an electrical transformer, when arranged in proximity with each other. The distances between the first and second induction coil can typically be increased when using resonant inductive coupling.
The charging unit (comprising the first induction coil) and the electronic device (comprising the second induction coil) are one particular example for an isolated electronic system comprising a first subsystem (e.g. the charging unit) and a second subsystem (e.g. the electronic device), wherein the first and second subsystems are galvanically isolated. It may be desirable to provide communication means between the first and the second subsystems, e.g. from the second subsystem to the first subsystem and vice versa. In the context of wireless charging such communication means may be used e.g. to inform the charging unit of the charging status of the battery comprised in the electronic device. The present disclosure describes a system and a method for enabling communication between the subsystems of an isolated electronic system in an efficient manner. The communication system and method described herein make use of the already available hardware components and can therefore be implemented in a cost efficient manner.